1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
|
/*
* Declarations for long-running block device operations
*
* Copyright (c) 2011 IBM Corp.
* Copyright (c) 2012 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef BLOCKJOB_H
#define BLOCKJOB_H
#include "block/block.h"
/**
* BlockJobDriver:
*
* A class type for block job driver.
*/
typedef struct BlockJobDriver {
/** Derived BlockJob struct size */
size_t instance_size;
/** String describing the operation, part of query-block-jobs QMP API */
BlockJobType job_type;
/** Optional callback for job types that support setting a speed limit */
void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
/** Optional callback for job types that need to forward I/O status reset */
void (*iostatus_reset)(BlockJob *job);
/**
* Optional callback for job types whose completion must be triggered
* manually.
*/
void (*complete)(BlockJob *job, Error **errp);
/**
* If the callback is not NULL, it will be invoked when all the jobs
* belonging to the same transaction complete; or upon this job's
* completion if it is not in a transaction. Skipped if NULL.
*
* All jobs will complete with a call to either .commit() or .abort() but
* never both.
*/
void (*commit)(BlockJob *job);
/**
* If the callback is not NULL, it will be invoked when any job in the
* same transaction fails; or upon this job's failure (due to error or
* cancellation) if it is not in a transaction. Skipped if NULL.
*
* All jobs will complete with a call to either .commit() or .abort() but
* never both.
*/
void (*abort)(BlockJob *job);
/**
* If the callback is not NULL, it will be invoked when the job transitions
* into the paused state. Paused jobs must not perform any asynchronous
* I/O or event loop activity. This callback is used to quiesce jobs.
*/
void coroutine_fn (*pause)(BlockJob *job);
/**
* If the callback is not NULL, it will be invoked when the job transitions
* out of the paused state. Any asynchronous I/O or event loop activity
* should be restarted from this callback.
*/
void coroutine_fn (*resume)(BlockJob *job);
/*
* If the callback is not NULL, it will be invoked before the job is
* resumed in a new AioContext. This is the place to move any resources
* besides job->blk to the new AioContext.
*/
void (*attached_aio_context)(BlockJob *job, AioContext *new_context);
/*
* If the callback is not NULL, it will be invoked when the job has to be
* synchronously cancelled or completed; it should drain BlockDriverStates
* as required to ensure progress.
*/
void (*drain)(BlockJob *job);
} BlockJobDriver;
/**
* BlockJob:
*
* Long-running operation on a BlockDriverState.
*/
struct BlockJob {
/** The job type, including the job vtable. */
const BlockJobDriver *driver;
/** The block device on which the job is operating. */
BlockBackend *blk;
/**
* The ID of the block job. May be NULL for internal jobs.
*/
char *id;
/**
* The coroutine that executes the job. If not NULL, it is
* reentered when busy is false and the job is cancelled.
*/
Coroutine *co;
/**
* Set to true if the job should cancel itself. The flag must
* always be tested just before toggling the busy flag from false
* to true. After a job has been cancelled, it should only yield
* if #aio_poll will ("sooner or later") reenter the coroutine.
*/
bool cancelled;
/**
* Counter for pause request. If non-zero, the block job is either paused,
* or if busy == true will pause itself as soon as possible.
*/
int pause_count;
/**
* Set to true if the job is paused by user. Can be unpaused with the
* block-job-resume QMP command.
*/
bool user_paused;
/**
* Set to false by the job while the coroutine has yielded and may be
* re-entered by block_job_enter(). There may still be I/O or event loop
* activity pending.
*/
bool busy;
/**
* Set to true by the job while it is in a quiescent state, where
* no I/O or event loop activity is pending.
*/
bool paused;
/**
* Set to true when the job is ready to be completed.
*/
bool ready;
/**
* Set to true when the job has deferred work to the main loop.
*/
bool deferred_to_main_loop;
/** Element of the list of block jobs */
QLIST_ENTRY(BlockJob) job_list;
/** Status that is published by the query-block-jobs QMP API */
BlockDeviceIoStatus iostatus;
/** Offset that is published by the query-block-jobs QMP API */
int64_t offset;
/** Length that is published by the query-block-jobs QMP API */
int64_t len;
/** Speed that was set with @block_job_set_speed. */
int64_t speed;
/** The completion function that will be called when the job completes. */
BlockCompletionFunc *cb;
/** Block other operations when block job is running */
Error *blocker;
/** BlockDriverStates that are involved in this block job */
GSList *nodes;
/** The opaque value that is passed to the completion function. */
void *opaque;
/** Reference count of the block job */
int refcnt;
/* True if this job has reported completion by calling block_job_completed.
*/
bool completed;
/* ret code passed to block_job_completed.
*/
int ret;
/** Non-NULL if this job is part of a transaction */
BlockJobTxn *txn;
QLIST_ENTRY(BlockJob) txn_list;
};
typedef enum BlockJobCreateFlags {
BLOCK_JOB_DEFAULT = 0x00,
BLOCK_JOB_INTERNAL = 0x01,
} BlockJobCreateFlags;
/**
* block_job_next:
* @job: A block job, or %NULL.
*
* Get the next element from the list of block jobs after @job, or the
* first one if @job is %NULL.
*
* Returns the requested job, or %NULL if there are no more jobs left.
*/
BlockJob *block_job_next(BlockJob *job);
/**
* block_job_get:
* @id: The id of the block job.
*
* Get the block job identified by @id (which must not be %NULL).
*
* Returns the requested job, or %NULL if it doesn't exist.
*/
BlockJob *block_job_get(const char *id);
/**
* block_job_create:
* @job_id: The id of the newly-created job, or %NULL to have one
* generated automatically.
* @job_type: The class object for the newly-created job.
* @bs: The block
* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
* @cb: Completion function for the job.
* @opaque: Opaque pointer value passed to @cb.
* @errp: Error object.
*
* Create a new long-running block device job and return it. The job
* will call @cb asynchronously when the job completes. Note that
* @bs may have been closed at the time the @cb it is called. If
* this is the case, the job may be reported as either cancelled or
* completed.
*
* This function is not part of the public job interface; it should be
* called from a wrapper that is specific to the job type.
*/
void *block_job_create(const char *job_id, const BlockJobDriver *driver,
BlockDriverState *bs, int64_t speed, int flags,
BlockCompletionFunc *cb, void *opaque, Error **errp);
/**
* block_job_add_bdrv:
* @job: A block job
* @bs: A BlockDriverState that is involved in @job
*
* Add @bs to the list of BlockDriverState that are involved in
* @job. This means that all operations will be blocked on @bs while
* @job exists.
*/
void block_job_add_bdrv(BlockJob *job, BlockDriverState *bs);
/**
* block_job_sleep_ns:
* @job: The job that calls the function.
* @clock: The clock to sleep on.
* @ns: How many nanoseconds to stop for.
*
* Put the job to sleep (assuming that it wasn't canceled) for @ns
* nanoseconds. Canceling the job will interrupt the wait immediately.
*/
void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
/**
* block_job_yield:
* @job: The job that calls the function.
*
* Yield the block job coroutine.
*/
void block_job_yield(BlockJob *job);
/**
* block_job_ref:
* @bs: The block device.
*
* Grab a reference to the block job. Should be paired with block_job_unref.
*/
void block_job_ref(BlockJob *job);
/**
* block_job_unref:
* @bs: The block device.
*
* Release reference to the block job and release resources if it is the last
* reference.
*/
void block_job_unref(BlockJob *job);
/**
* block_job_completed:
* @job: The job being completed.
* @ret: The status code.
*
* Call the completion function that was registered at creation time, and
* free @job.
*/
void block_job_completed(BlockJob *job, int ret);
/**
* block_job_set_speed:
* @job: The job to set the speed for.
* @speed: The new value
* @errp: Error object.
*
* Set a rate-limiting parameter for the job; the actual meaning may
* vary depending on the job type.
*/
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
/**
* block_job_cancel:
* @job: The job to be canceled.
*
* Asynchronously cancel the specified job.
*/
void block_job_cancel(BlockJob *job);
/**
* block_job_complete:
* @job: The job to be completed.
* @errp: Error object.
*
* Asynchronously complete the specified job.
*/
void block_job_complete(BlockJob *job, Error **errp);
/**
* block_job_is_cancelled:
* @job: The job being queried.
*
* Returns whether the job is scheduled for cancellation.
*/
bool block_job_is_cancelled(BlockJob *job);
/**
* block_job_query:
* @job: The job to get information about.
*
* Return information about a job.
*/
BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
/**
* block_job_pause_point:
* @job: The job that is ready to pause.
*
* Pause now if block_job_pause() has been called. Block jobs that perform
* lots of I/O must call this between requests so that the job can be paused.
*/
void coroutine_fn block_job_pause_point(BlockJob *job);
/**
* block_job_pause:
* @job: The job to be paused.
*
* Asynchronously pause the specified job.
*/
void block_job_pause(BlockJob *job);
/**
* block_job_resume:
* @job: The job to be resumed.
*
* Resume the specified job. Must be paired with a preceding block_job_pause.
*/
void block_job_resume(BlockJob *job);
/**
* block_job_enter:
* @job: The job to enter.
*
* Continue the specified job by entering the coroutine.
*/
void block_job_enter(BlockJob *job);
/**
* block_job_ready:
* @job: The job which is now ready to complete.
*
* Send a BLOCK_JOB_READY event for the specified job.
*/
void block_job_event_ready(BlockJob *job);
/**
* block_job_cancel_sync:
* @job: The job to be canceled.
*
* Synchronously cancel the job. The completion callback is called
* before the function returns. The job may actually complete
* instead of canceling itself; the circumstances under which this
* happens depend on the kind of job that is active.
*
* Returns the return value from the job if the job actually completed
* during the call, or -ECANCELED if it was canceled.
*/
int block_job_cancel_sync(BlockJob *job);
/**
* block_job_cancel_sync_all:
*
* Synchronously cancels all jobs using block_job_cancel_sync().
*/
void block_job_cancel_sync_all(void);
/**
* block_job_complete_sync:
* @job: The job to be completed.
* @errp: Error object which may be set by block_job_complete(); this is not
* necessarily set on every error, the job return value has to be
* checked as well.
*
* Synchronously complete the job. The completion callback is called before the
* function returns, unless it is NULL (which is permissible when using this
* function).
*
* Returns the return value from the job.
*/
int block_job_complete_sync(BlockJob *job, Error **errp);
/**
* block_job_iostatus_reset:
* @job: The job whose I/O status should be reset.
*
* Reset I/O status on @job and on BlockDriverState objects it uses,
* other than job->blk.
*/
void block_job_iostatus_reset(BlockJob *job);
/**
* block_job_error_action:
* @job: The job to signal an error for.
* @on_err: The error action setting.
* @is_read: Whether the operation was a read.
* @error: The error that was reported.
*
* Report an I/O error for a block job and possibly stop the VM. Return the
* action that was selected based on @on_err and @error.
*/
BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
int is_read, int error);
typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
/**
* block_job_defer_to_main_loop:
* @job: The job
* @fn: The function to run in the main loop
* @opaque: The opaque value that is passed to @fn
*
* Execute a given function in the main loop with the BlockDriverState
* AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and
* anything that uses bdrv_drain_all() in the main loop.
*
* The @job AioContext is held while @fn executes.
*/
void block_job_defer_to_main_loop(BlockJob *job,
BlockJobDeferToMainLoopFn *fn,
void *opaque);
/**
* block_job_txn_new:
*
* Allocate and return a new block job transaction. Jobs can be added to the
* transaction using block_job_txn_add_job().
*
* The transaction is automatically freed when the last job completes or is
* cancelled.
*
* All jobs in the transaction either complete successfully or fail/cancel as a
* group. Jobs wait for each other before completing. Cancelling one job
* cancels all jobs in the transaction.
*/
BlockJobTxn *block_job_txn_new(void);
/**
* block_job_txn_unref:
*
* Release a reference that was previously acquired with block_job_txn_add_job
* or block_job_txn_new. If it's the last reference to the object, it will be
* freed.
*/
void block_job_txn_unref(BlockJobTxn *txn);
/**
* block_job_txn_add_job:
* @txn: The transaction (may be NULL)
* @job: Job to add to the transaction
*
* Add @job to the transaction. The @job must not already be in a transaction.
* The caller must call either block_job_txn_unref() or block_job_completed()
* to release the reference that is automatically grabbed here.
*/
void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
/**
* block_job_is_internal:
* @job: The job to determine if it is user-visible or not.
*
* Returns true if the job should not be visible to the management layer.
*/
bool block_job_is_internal(BlockJob *job);
#endif
|